Vocal cards are used to purchase another vocal ver. of songs at the song store.
How to obtain
Vocal cards are given out three times, for when a character has reached [[]]s bussy bussy , busy3, and 43. Alternatively, vocal cards may be obtained using vocal card exchange tickets. For original characters (such as Hoshino Ichika), their unit specific vocal card exchange ticket may be used. For Ichika, the Leo/need ticket may also be used. However, for VIRTUAL SINGER characters (such as len kagamine forever), there is no VIRTUAL SINGER vocal card exchange ticket.
How to use
you dont lol